Tracking the maintenance of railways

February 10, 2018

The Konux ‘KORA’ is a wireless sensor on the track that collects acceleration and vibration data to provide a more efficient train service.
As more and more trains run on the British railways, efficient track maintenance has become essential.

The number of trains using the rail network has doubled in the last 10 years and the number of passengers is expected to increase by 40% by 2040. According to Network Rail, the biggest challenge is managing the increased capacity.

The UK rail network was not designed to meet this demand, resulting in reduced track life and improved maintenance efficiency.

As technology has evolved, rail maintenance and maintenance has become easier, moving from traditional, labor-intensive manual maintenance to much more robust solutions. faster, safer, more accurate and more efficient.

For example, sensors are used to monitor runway areas such as turnouts and track circuits, which, according to Network Rail, are increasing in use.

The sensors are stationary and consist of edge processing, which is transmitted via GSN with O2 SIM cards to Network Rail’s Wonderware SCADA system.

“This allows us to monitor the track condition and define the priorities we need to focus on,” says Tim Flower, Maintenance Manager at Network Rail.

“The maintenance of the rails is to understand that an error will occur,” he adds. “We use the data collected by technology, such as sensors, to detect a trend, to avoid errors, so that accurate forecasts can be made, so that we can see what is going wrong, when it will fail, and hopefully. that it will fail. ”

To help rail operators, Konux, a German sensor manufacturer, has developed an intelligent IoT sensor solution system called KORA, which monitors and analyzes the status of switches.

According to its CEO, Andreas Kunze, the change or “point” is one of the most important elements of the road and accounts for 20% of train delays in Europe.

As one of the only moving parts of the rail, the switch can be a fragile component, but is an integral part of the railway line, as the rails connect to it.

“If that fails, it will cause a chain reaction, rendering several parts of the road unusable,” Kunze explains.

On some of Network Rail’s busiest lines, more than 100 trains will run in one set of points in one day. Therefore, it is crucial that rail traffic maintains it well.

KORA monitors the state of railway installations and measures wireless elements such as acceleration, vibration and communication via GSM. The raw data is pre-processed in the sensor, selecting only the data needed for more efficient transmission. This data is then sent to Konux’s backend system and merged with the data Konux has received from its customers. For example, information on weather, schedules and point machines (closing and opening of the track).

Artificial intelligence is then used to identify and evaluate problems in these data – the system comparing the “digital footprint” of healthy assets with the results of continuous monitoring and showing anomalies.

“We are helping railways move away from inspection protocols, which are very expensive so far,” Kunze said.

He emphasizes the importance of a wireless system. “In the train, you do not want cables everywhere – every meter costs thousands, but working wireless means that battery management is important.

“The development of both low-power systems and communication systems has really helped keep up with maintenance,” he says. “Advances in communications technology allow us to send more data faster, and even if we control the power supply, we can limit the maintenance of the sensor itself and the train companies do not want to replace new parts all the time. the months.

According to Kunze, the materials used were another important consideration. “It has to be robust, not just in terms of mounting, but the whole thing has to deal with shocks and bad weather.”

Above: The KORA data processes are sent to the Konux backend system, where they are merged with the data provided by the customer, such as time schedules
By developing its MEMS piezoelectric hybrid sensors, Kunze explains that Konux has spent three years proving that the product can survive in a harsh environment.

Difficult conditions

However, a difficult environment is not always a problem. In fact, Network Rail uses these conditions to its advantage. The sensor system provided by Perpetuum draws its energy from the movement of the train to provide itself.

In addition to the 60,000 sensors it has deployed, Network Rail also uses image processing systems and ultrasonic inspection to inspect track damage, a difficult, time-consuming and uncertain task for workers.

Network Rail has a series of trains that measure different types of equipment to understand how they work with the basic parameters. This technology is used to measure track geometry and simple linear pattern using linear scanning, 3D and thermal imaging cameras to scan the track as it passes under the “gauge train”.

“We can not only monitor each day, but also on time, reducing the number of one-off errors by about 30% and reducing circuit downtime by 25%.”
– Tim flower
These cameras record raw images up to 76 kHz, allowing you to capture images at speeds up to 125 mph. Cameras store device information, download it to an on-board computer and decode it by image processing software, synchronized with the positioning system and geometric data in real time and analyzed by a train inspector. . Reports are sent to ground crews to locate errors.

Ultrasonic testing is used to identify cracks in the human eye that often occur in railheads because of the stress concentrations at these geometric discontinuities.

A team of researchers at the University of California is developing a solution to the problem of “air gaps” currently encountered in traditional examination methods.

According to Assistant Professor Sheng Xu of the University of California, because of the curved nature of the rail heads, it is difficult to maintain firm interface contact and thus good coupling with irregular non-planar surfaces. This can lead to large acoustic energy reflections and wave distortions, resulting in unreliable test results. Defects such as detail fracture and transverse cracking can not be tested from the top of the rail and require the operator to hold the transducer on the side of the rail. According to Professor Sheng, this takes time, requires a lot of work and can lead to inaccurate measurements.

Professor Sheng and his team are developing an expandable membrane ultrasonic probe that uses a series of thin piezoelectric composites 1-3 as transducers, traces of multilayer serpentine metals as electrical interconnects, and low modulus elastomeric membranes using encapsulating materials.

“Flexible elastomeric encapsulation materials allow the device to conform closely to the railhead side, providing excellent acoustic coupling.The” island bridge “arrangement provides biaxial extensibility of more than 50% with Minimal impact Transformer performance allows the unit to operate on non-flat tracks, “said Hongjie Hu, a member of the California team.

Despite the “proximity to commercialization,” the team says they must first improve spatial resolution to improve image accessibility and accuracy.

According to Flower, the most valuable processing electronics is real-time monitoring of plant performance. “Not only can we monitor day by day,” he says, “but from one hour to the next, reducing the number of one-off errors by about 30 percent and reducing interruptions by 25 percent. circuit.”

Flower expects rail infrastructure to evolve from manual maintenance to an “almost factory-owned inspection system”. He cited the main projects on the rail network and technology, including automated tunnel inspection and pantograph monitoring.

The challenge is to find a balance between accuracy, repeatability, information and cost. “We need to improve maintenance without having to worry about managing large amounts of data,” he concludes.

And with Network Rail planning to introduce 7,000 new cars on the rail network by 2021 and 6,400 new trains, we hope the balance will be quick and that these big projects will stay on track.